can't handle the host being down because kcp transport swallows send errors

[tycobbb]

Describe the bug if you try to connect to a host that is down or unreachable, the kcp client spams error logs, does not attempt to disconnect, and provides no way to handle the error.

[IMPORTANT] How can we reproduce the issue, step by step: sorry, i haven't looked at your built-in examples but i imagine this is trivial to reproduce.

• start a game with network manager wired up to a kcp client
• don't start any host
• attempt to connect a valid ip
• the client will spam errors

Expected behavior the client does not swallow errors (it swallows them on this line), and provides a way to handle the error so that it can be detected in user code and the player can be disconnected.

Screenshots none.

Desktop (please complete the following information):

• OS: macOS
• Build target: standalone
• Unity version: 2021.2.15
• Mirror branch: master

Additional context none

[tycobbb]

wait this is not true, it just hits the timeout oops.